Means for cooling electrical apparatus



E. B. CLARKE MEANS FOR COOLING ELECTRICAL APPARATUS 2 Sheets-Sheet 1 April 28, 1931.

Filed Feb. 17, 1928 INVENTOR A'TTORNEY April 28, 1931. E. B. CLARKE MEANS FOR COOLING ELECTRICAL APPARATUS Filed Feb. 17, 1928 2 Sheets-Sheet 2 TORNEY Patented Apr. 28, 1931 UNITED STATES PATENT QFFICE EARL B. CLARKE, 0F LAFAYETTE, INDIANA, ASSIGNOR TO VJESTINGI-IOUSE ELECTRIC 8c MANUFACTURING COMPANY, A CGR-PORATION OF IDENNS'ILVANIA MEANS FOB CCG-LING ELECTRICAL APPARATUS Application led February 17, 1928.

My invention relates to means for cooling electrical apparatus and has particular reference to electrical transforming apparatus.

In electrical transforming apparatus and the like, it is necessary to dissipate the heat generated by the operation of such apparatus in a simple and eiiicient manner.

One of the means now used, to which my invention has particular reference, comprises immersing the electrical apparatus in an insulating and heat conducting fiuid such as oil having a high dielectric strength. It has been found in such means that the surface of the tank for containing the oil did not have a suflicient radiating surface for dissipating the heat generated by the electrical apparatus to raise the temperature of the oil. Therefore, to increase the radiating surface to cool the oil more quickly, a plurality of tubular members were disposed in banks about the periphery of the transformer casing. These tubular banks or radiators greatly increased the radiating surface in contact with the oil and cooled the latter more quickly and effectively.

I have found that the efficiency and usefulness of thi-s type of apparatus may be greatly increased by blowing streams of air onto thesides of each bank so that they meet and form a resultant stream of air that rises vertically upward, parallel with and in contact relationship with the heat dissipating' surfaces of the radiator tubes.

My invention, however, may be more readi ily understood if the accompanying drawings are consulted in connection with the following description.

In the drawings:

Figure l is a view in elevational perspective of a transformer casing having cooling apparatus associated therewith and constructed'in accordance with my invention.

Fig. 2 is a plan view of a portion of the transformer casing shown in Fig. l having a portion thereof broken away.

Fig. 3 is a view, similar to Fig. 2, of a modification of my invention; and

Fig. 4 is a view in side elevation of the device shown in Fig. 3.

Referring to Fig. 1, a system constructed Serial No. 254,961.

in accordance with my invention comprises a tank or casing 2 that is provided with radiators 3 that communicate with the upper and lower part of the tank 2 through pipes 4.-. Transforming apparatus (not shown) is disposed within the casing 2 and is connected by conducting leads to terminals 5 that are insulated from the cover 6 of the transformer casing 2 by insulating bushings 7.

The casing 2, the radiators 3 and the connections a' contain a suitable cooling and insulating` medium Qa. such as an oil of high dielectric strength, the heat generated in the transformer causing a thermal circulation of the cooling medium through the radiators where this heat is transferred to the surrounding atmosphere and dissipated.

The radiators 3 comprise a plurality of vertical substantially parallel tubular members 8 that materially increase the radiating surface for dissipating the heat of the oil that passes through them. To the end that air `iets may be directed against the radiator tubes, I dispose about the casing Q. preferably-in a region midway of its ends, an ai f jacket or duct 9 to which radial air ducts l0 are connected. The duct S), preferably, is separated from the casing 2 by a space ll for permitting the normal upward movement of the heated air near the surface of the casing 2.

The radial air ducts l0 are disposed in facing relation on opposite sides of each of the radiators 3 and each is provided with an elongated opening or passage l2, thc relation being such that the air jets emitted from the openings l2 on opposite sides of a radiator 3 move into the central area of the radiator at an angle with respect to the radiator tubes so that the two jets of air meet and form a single upward current of air. This upward current of air has a velocity equal to the resultant of the velocities of the two air jets that meet to form it.

Usually, the inner tubes of any radiator 3 are at higher temperature than are the outer tubes of that radiator because said inner tubes are surrounded by other heat dissipating tubes. In accordance with my invention, the

air jets from the openings 12 meet near these inner tubes at a relatively high velocity and, therefore, cool them emciently. The flow of air upwardly around the surfaces of the radiating tubes from the openings 12 creates a suction effect with resultant movement of the air around these portions of the radiating tubes below said openings 12.

All of the air passageways are mounted, preferably, so that they will be some distance away from the surfaces of the tank and radiators, for example, about 11/2 inches more or less. This completely prevents the air passageways from blanketing the radiator and tubes.

Air may be supplied to the central air duct 9 in any suitable manner as, for example, by a centrifugal blower 15 that is driven by a motor (not shown) enclosed in a housing 1G. Air is directed to the chamber 9 through a conduit 17 suitably secured thereto. lhe blower 15 and the housing 16 are mounted, preferably, on U beams 18 that, in turn, are mounted on the transformer supporting frame 19.

In Figs. 3, and 4, Iliave illustrated another cooling system in which radiators 3 are arranged in banks, all of them being disposed on one side of the transformer casing 2 and preferably suspended from a pipe 13 receiving hot oil from the top of the transformer casing 2 andV passing it into the y'adiators 3 from which it flows by the lower pipe 14 back into the tank 2.

To thus dispose the radiators 3 in the manner illustrated in lFigs. 3 and 4 is desirable because such a dispositionof them leaves a large portion of the tank 2 substantially free from blanketing and, therefore, leaves the latter free to dissipate heat in an efficient manner. In this modification the number of radiators may be increased indefinitely, permitting of the size of the main tank to be decreased to a minimum.

A central air duct 2O is provided between the two rows 21 and 22 of radiators 3 and said duct has passage forming structures 23 projecting from it into the space between adjacent radiators 3. The radiators 3 are suitably spaced apart for the reception of the structures 23 which are spaced a short distance from the surface of the radiator tubes so as not to prevent the natural circulation of air around them as set forth above. The main air duct 2O is located, preferably, midway between the ends` ofthe radiators 3. A baflie Wall 24 is mounted in each of the structures 23 so that the air will divide, a portion going toward each of the radiators. As eX- plained above in connection with Figs. l and 2, an elongated port opening l12 is provided in the sides and near the top ofthe structures 23. The action of the air in meeting and forming a current of air parallel-With lthe tubes of the radiatoris similar -to that en plained above in connection with Figs. 1 and 2.

A centrifugal blower 15 supplies air at the desired pressure to the main air duct 20. The air blower 15 may be driven in any suitable manner as, for example, by a motor 25 whose shaft may be directly coupled to the shaft of blower 15.

An oil circulatin(r device comprising a motor 26 and a pump 27 driven thereby may be utilized with the form of my invention illustrated in Figs. 3 and Il, the pump 27, preferably, being inserted in the lower pipe 1li between the transformer tank 2 and the radiators 3.

The above-described apparatus is especially suited for coolino' very large sel f-cooled transformers and mai-:es possible the application of heavy overloads on a normally self-cooled transfm'mcr or provides means.

for reducing the number of radiators that would normally be necessary if air and oil under forced circulation were not utilized.

,lt will be apparent to those skilled in the art that my invention is readily applicable to any type of heat-radiating apparatus and is no wise limited to the cooling of electrical transformers. It will also be apparent to those skilled in the artthat a particularly desirable feature of my invention lies inthe method of cooling a plurality of tubes having radiating surfaces which comprises generating and directing a plurality of currents of air to the said tubes so that the said currents meet and form a resultant current of air that passes upwardly in Contact with the surfacesl of the tubes.

Various changes may be made in my invention without departing from the spirit and scope thereof as set forth in the appended claims.

I claim as my invention:

1. In combination, a tank, a plurality of radiators mounted on said tank, said radiators being disposed in spaced banks around the periphery of said tank, a central air duct embracing said Itank having radial air ducts, each of said radial air ducts having a port opening on one side of a `bank of said radiators, and means for supplying air under pressure to saidcentral air duct.

2. In combination, a radiator comprising a plurality of vertically disposed tubular -members, lmeans lfor blowing air upwardly adjacent to said tubular members `including Apairs of air ducts disposedon opposite sides of saidradiators, each pair of said ducts having elongated openings facing Veach other, and sloping fbafiie .plates disposed above said openings :for causing the air 4issuing from said openings to meet atan angle near the center ofthe radiator and assume a `vertical resultant vdirection of movement. 3. A cooling apparatus including a tank containing a heated liquid, radiators :associate'd therewith and disposed around the periphery of said tank, a central air duct spaced from and embracing said tank and having discharge ducts extending therefrom, each discharge duct being provided with an air outlet port adjacent to a radiator, and means for supplying air under pressure to said central air duct.

4. A cooling apparatus for a transformer including a tank containing a heated liquid, radiators associated therewith for removing heat from said liquid, a central air duct around said tank, and means for directing a cooling Huid from said duct to the surfaces of said radiators, said means including a plurality of tapered box-shaped ducts each radiating from the central duct along the surface of said radiators.

In testimony whereof I have hereunto subscribed my name this 9th day of February,

EARL B. CLARKE. 

